It is quite desirable to provide an improved yet inexpensive, rugged and flexible electric circuit controlling device having the capability to be used for a number of diverse applications with little change of components. In addition, the device should be able to control selectively multiple electric circuits even under adverse operating conditions. For example, it is quite desirable to provide an improved circuit controlling device that is sturdy enough to be employed in vehicles, such as automobiles. In one application where the vehicle is equipped with a hydraulic boost power brake system, the device should control the cycling of a hydraulic pump for maintaining a specified pressure in the boost chamber. If this pressure falls below a critical point, the control then turns on a warning light on a dashboard. With very little change in components, if any, the device could also be used for another multiple circuit controlling application in which the vehicle has an air conditioning system. The device would be connected into the high side of the air conditioning system and could be capable of opening and closing a fan circuit of that system as well as switching the fan between low and high speeds. Further it would be especially desirable to incorporate in such multiple circuit controlling devices, a low cost but highly effective single snap acting arrangement which could operate with at least two snap actions for operating two switches at different settings to accomplish the multiple circuit controlling functions. This should be attained by an arrangement that has an enhanced life expectancy and is reliable in operation. Further, it would be further desirable that the device incorporate an improved way to calibrate the forces in the snap acting arrangement.